Insecticidal and miticidal compositions

ABSTRACT

This invention relates to an insecticidal and miticidal composition which contains as active ingredients chlorfenapyr in combination with one or more compounds selected from the group consisting of benzoepin, nereistoxin-type insecticidal agents and diafenthiuron.

This application is a 371 of PCT/JP97/04273, filed Nov. 25,1997.

DESCRIPTION

1. Field of the Invention

This invention relates to insecticidal and miticidal compositions whichcontain as active ingredients4-bromo-2-(4-chlorophenyl)-l-(ethoxymethyl)-5-(trifuloromethyl)pyrrole-3-carbonitrile(hereinafter referred to as chlorfenapyr) in combination with a secondinsecticidal and miticidal ingredient(s) which can be effectivelyapplied especially in the agrohorticultural field.

2. Background of the Invention

Chlorfenapyr, which is an active ingredient of the insecticidal andmiticidal composition of the invention, is known to be effective againstinsects such as Hemiptera pests such as leafhoppers (DoItocephalidae),Lepidoptera pests such as diamond back moth (Plutella xylostella),common cutworm (Spodoptera litura) and apple leafminer (Phyllonorycterringoniella) and Thysanoptera pests such as Thrips palmi and yellow teathrips (Spirtothrips dorsalis) and agrohorticultural pests such as mitessuch as two-spotted spider mite (Tetranychus urticae koch), Kanzawaspider mite (Tetranychus kanzawai kishida) and Aculops pelekassi.

The second active ingredient of the insecticidal and miticidalcomposition of the invention includes one or more of the followingcompounds: hexachlorohexahydromethanobenzodioxathiepine oxide [benzoepin(endosulfan)]; Nereistoxin-type insecticidal agents such as1,3-bis-(carbamoylthio)-2-(N,N-dimethyl-amino)propane hydrochloride(cartap), 5-dimethyl-amino-1,2,3-trithiane oxalate (thiocyclam) and thelike; and 1-tert-butyl-3-(2,6-diisopropyl-4-phenoxyphenyl)-thiourea(diafenthiuron), all of which are known to be effective agents againstagricultural pests such as Hemiptera, Lepidoptera and Coleopterainsects.

Although insecticidal and miticidal agents have been developed in orderto control various pests such as agrohorticultural pests or hygienicpests and in practice have been used as a single or a mixed agent, pestswhich have acquired resistance against various agents have beenappearing as a result of the repeated use of these agents.

In particular, important economic pests in agrohorticulture such asTetranychidae, which have a propensity to easily develop resistanceagainst pesticidal agents due to their ability to deposit large numbersof eggs and produce large numbers of generations which, themselves,require only a few days for development are of great concern. Resistancedevelopment in this pest family is also favored by a high mutation rateand frequent inbreeding, due to minimal migration. For these reasons,two-spotted spider mite (Tetranychus urticae koch), Kanzawa spider mite(Tetranychus kanzawai kishida), Aculops pelekassi, and the like haveacquired resistance, to some degree, against almost all existingpesticidal agents. Therefore, in order to prevent and control the damagecaused by Tetranychidae, development of a new insecticidal and miticidalagent which shows a high effect against Tetranychidae which haveacquired resistance against the conventional miticidal agents is highlydesirable.

However, to obtain an insecticidal and miticidal composition which showsno cross-resistance with existing insecticidal and miticidal agents, hasno toxicity problems and has little negative impact on the environment,is extremely difficult. Therefore, a means to delay or prevent thedevelopment of resistant strains of pest species is always being sought.In order to apply an effective agent as long as possible, a rotationalapplication of agents with different mechanisms of action is adopted forgood pest management practice. However, this approach does notnecessarily give satisfactory pest control. Therefore, after aresistance problem has occurred, a countermeasure to resistance bycombining insecticidal and miticidal agents has been studied. However, ahigh synergistic action has not always been found.

Therefore, it is an object of this invention to provide an insecticidaland miticidal composition which demonstrates a high controlling effecteven against Tetranychidae which have acquired resistance againstchlorfenapyr.

SUMMARY OF THE INVENTION

In order to establish a countermeasure to a resistance problem inTetrachychidae against chlorfenapyr before such a problem occurs, thesynergistic action with the existing insecticidal, miticidal andfungicidal agents was studied using resistant species which have beenartificially established in the laboratory by selecting Tetrachychidaewhich have been treated with chlorfenapyr. Thus, it has now been foundthat an insecticidal and miticidal composition which contains as activeingredient chlorfenapyr in combination with one or more compoundsselected from the group consisting of benzoepin, nereistoxin-typeinsecticidal agents and diafenthiuron shows a joint action orsynergistic effect which could not be foreseen from each individualingredient alone.

DETAILED DESCRIPTION OF THE INVENTION

Chlorfenapyr, which is an active ingredient of the insecticidal andmiticidal composition of the invention, is a known compound (JapaneseLaid-open (Kokai) Patent Publication.No. 104042/89). Compounds which aresuitable for use as the second active ingredient in the composition ofthe invention such as one or more of the following compounds:

1) Benzoepin (6,7,8,9,10,10-hexachloro- 1,5,5a,9,9a-hexahydro-6,9-methano-2,4.3-benzodioxathiepin-3-oxide),

2) Nereistoxin-type insecticidal agents such as Cartap(1,3-bis(carbamoylthio)-2-(N,N-dimethylamino)propane hydrochloride),Thiocyclam (5-dimethylamino-1,2,3-trithiane oxalate) and Bensultap(S,S′-2-dimethylaminotrimethylene-di(benzenethiosulfonate), preferablycartap and thiocyclam, and

3) Diafenthiuron(1-tert-butyl-3-(2,6-diisopropyl-4-phenoxyphenyl)thiourea)

(hereinafter referred to as Group A) are all known compounds and arecommercial products which are readily available.

For the preparation of the insecticidal and miticidal composition of theinvention, it is suitable to formulate as a wettable powder, aqueousconcentrate, emulsion, liquid concentrate, sol (flowable agent), powder,aerosol, or the like, by conventional methods such as admixingchlorfenapyr and one or more compounds of Group A with a suitablecarrier and auxilliaries, such as emulsifiers, dispersants, stabilizers,suspending agents, penetrants, and the like.

The content of the total active ingredients of the composition of theinvention, expressed as weight/weight %, is preferably in the range ofabout 1-90% for wettable powder, aqueous concentrate, emulsion, liquidconcentrate and sol formulations. The preferable content of total activeingredients is about 0.5-10% for powder formulations and about 0.01-2%for aerosol formulations.

Carriers suitable for use in the insecticidal and miticidal compositionsof the invention may be any solid or liquid carrier which is commonlyused for an agrohorticultural composition. Various surfactants,stabilizers and other auxiliary ingredients may be used according to thenecessity. In commercially useful formulations, the composition of theinvention may also be present in a mixture with other active agents, forexample various insecticidal, miticidal, fungicidal and herbicidalagents, plant growth regulators, repellants, attractants, synergists andfertilizers and fragrances, in order to expand its applicability.

The ratio of chlorfenapyr to the compound(s) of Group A in theinsecticidal and miticidal composition of the invention is about 1weight part of chlorfenapyr to about 0.01-100 weight parts, preferablyabout 1-20 weight parts, of a compound(s) of Group A.

The insecticidal and miticidal composition of the invention isparticularly effective for the control of Tetranychidae such astwo-spotted spider mite (Tetranychus urticae koch), Tetranychuscinnabarinus (boisduyal), Kanzawa spider mite (Tetranychus Kanzawaikishida), Tetranichus viennensis zacher, and the like.

Advantageously, the insecticidal and miticidal composition of theinvention shows not only a synergistic miticidal effect against theabove-mentioned Tetranychidae, but also demonstrates simultaneouscontrol of troublesome pests such as leafroller moths (Tortricidae),Carposinidae, leafminer moths (Lyonetiidae), plant bugs (Pentatomidae),aphids (Aphididae), leafhoppers (Deltociphalidae), thrips (Thripidae),aphids (Aphididae), diamond back moths (Plutella xylostella), Mamestrabrassicae, leaf beetles (Chrysomelidae), whiteflies (Aleyrodidae) andthe like on important agronomic crops such as fruit trees, for examplecitrus, apple and pear; tea plants; vegetables and the like.

Although the application amount may differ according to prevailingconditions such as the population density, the kinds and cultivationform of the target crop, the weather conditions, the manner ofapplication, and the like, in general, the total amount of chlorfenapyrin combination with the compound(s) of Group A is about 0.1-1,000 g,preferably about 40-500 g per 10 ares. In actual practice, thecomposition of the invention when in the form of a wettable powder,aqueous concentrate, emulsion, liquid concentrate, sol, or the like maybe diluted with water and applied to the crop at an application rate ofabout 100-700 liters per 10 ares. When the inventive composition isformulated as a powder or aerosol, the crop may be treated with theundiluted formulation.

The insecticidal and miticidal composition of the invention is furtherillustrated in the examples set forth hereinbelow. These examples arenot intended to limit the scope of the invention.

EXAMPLE 1

FORMULATION EXAMPLE 1 EMULSION

Clorfenapyr 5 parts Benzoepin 40 parts Xylene 25 parts Dimethylformamide 20 parts Sorpol 3005X 10 parts

(Polyoxyethylene type surfactant manufactured by Toho Chemical IndustryCo., Ltd., commercial name)

An emulsion is obtained by mixing homogeneously and dissolving theabove-mentioned ingredients.

EXAMPLE 2

FORMULATION EXAMPLE 2 WETTABLE POWDER

Chlorfenapyr 5 parts Thiocyclam 50 parts Carplex #80 10 parts (Whitecarbon manufactured by Shionogi & Co., Ltd, commercial name) Zeeklite SP22 parts (Mixture of kaolinite and cericite manufac- tured by ZeekliteInd., commercial name) Calcium ligninsulfonate 8 parts

A wettable powder is obtained by homogeneously mixing theabove-mentioned ingredients by jet air mill.

EXAMPLE 3

FORMULATION EXAMPLE 3 SOL (FLOWABLE AGENT)

Chlorfenapyr 5 parts Diafenthiuron 25 parts Ethylene glycol 8 partsSorpol AC3020 5 parts (Toho Chemical Ind. Co., Ltd., commercial name)Xanthan gum 0.1 parts Water 56.9 parts

Chlorfenapyr, diafenthiuron and a previously prepared mixture ofethylene glycol, Sorpol AC3020 and xanthan gum are well mixed in waterand dispersed. This slurry is then wet pulverized by Dynomill (ShinmaruEnterprises) to obtain a sol (flowable agent).

EXAMPLE 4

FORMULATION EXAMPLE 4 POWDER

Chlorfenapyr 0.5 parts Cartap 3.5 parts White carbon 5.0 parts Clay 91parts (Nippon Talc Co., Ltd.)

The above-mentioned ingredients are homogeneously mixed and pulverizedto obtain a powder

Each of the above-prepared formulations is suitable to be used as anagrochemical.

EXAMPLE 5

TEST EXAMPLE I

In this experiment, the miticidal effect against female imagines(adults) of Kanzawa spider mite (Tetranychus kanzawai kishida) which areresistant to chlorfenapyr is evaluated.

Round leaf disks (2 cm diameter) are cut out of a first leaf of kidneybean by a leaf punch and 4 sheets of the disks are placed on wetsanitary cotton in a plastic cup (8 cm diameter). On each leaf disk, 4female imagines of Kanzawa spider mite (Tetranychus kanzawai kishida)which had acquired a strong resistance to chlorfenapyr are inoculated.

After the inoculation, chlorfenapyr and a compound(s) selected fromgroup A are dispersed in water containing 200 ppm of an extender (Sorpol3005×) and diluted such that a predetermined concentration of activeingredient is obtained. Each plastic cup is sprayed with 3.5 ml of atest solution with a rotary spray tower (Mizuho Scientific Co., Ltd.)and stored in a constant temperature chamber held at 25°±1° C. (32individuals are tested per concentration, 4-5 concentrations areevaluated per formulation and 2 performances are repeated). Two daysafter treatment, the number of living and dead female imagines ofKanzawa spider mite (Tetranychus kanzawai kishida) which had acquired astrong resistance to chlorfenapyr is counted and the mortality (%) iscalculated according to the formula shown hereinbelow.${{Mortality}\quad (\%)} = {\frac{{Number}\quad {of}\quad {dead}\quad {mite}}{{{Number}\quad {of}\quad {alived}\quad {mite}} + {{Number}\quad {of}\quad {dead}\quad {mite}}} \times 100}$

Using these data, the LC₅₀ values are obtained by conventional probitanalysis techniques. A co-toxicity coefficient is calculated by applyingSun and Johnson's formula (J. Econ. Ent., Vol 53, p. 887, 1980) which isgenerally used to determine the degree of synergistic activity.

The LC₅₀ value of each individual effective ingredient which constitutesthe insecticidal and miticidal composition of the invention is shown inTable I. The LC₅₀ values and the co-toxicity coefficients of thecomposition of the invention are shown in Table II.

Co-toxicity coefficient=T^(c)$T^{c} = {\frac{{Actual}\quad {toxicity}\quad {index}\quad {of}\quad {mixture}}{{Theoretical}\quad {toxicity}\quad {index}\quad {of}\quad {mixture}} \times 100}$

For T^(c) values greater than 100, the greater value indicates astronger synergistic action. For a T^(c) value equal to 100, an additiveaction is indicated. For T^(c) values less than 100, the lesser valueindicates a greater antagonistic action. A more detailed description ofthe calculation of the co-toxicity coefficient using theabove-referenced Sun and Johnson formula follows.

The LC₅₀ values of Test Compound A alone and Test Compound B alone andthe LC₅₀ value of the (A+B) mixture M is determined.

Actual toxicity index of mixture M=M^(ti)

Each LC₅₀ value of effective ingredient A and effective ingredient B andthe LC₅₀ value of the mixture of A+B are used to determine the actualtoxicity index as shown in the equation below.$M^{ti} = {\frac{{LC}_{50}\quad {of}\quad A}{{LC}_{50}\quad {of}\quad M} \times 100}$

Theoretical toxicity index of mixture M=Th.M^(ti)

Th.M^(ti)=(Toxicity index of A×% A in M+Toxicity index of B×% B in M)

Toxicity index of B=B^(ti)$B^{ti} = {\frac{{LC}_{50}\quad {of}\quad A}{{LC}_{50}\quad {of}\quad B} \times 100}$

Toxicity index of A=A^(ti)

A^(ti)=100

TABLE I Evaluation Of The Effect Of Test Compounds Against Female ImagoOf Kanzawa Spider Mite Which Have Acquired Resistance AgainstChlorfenapyr TEST COMPOUND LC₅₀ (ppm) Chlorfenapyr 1500 Benzoepin 600Cartap 2300 Thiocyclam 230 Diafenthiuron 540

By comparison, the LC₅₀ value for chlorfenapyr against a susceptiblestrain of spider mite is about 5 ppm.

As can be seen from the data on Table I, the resistant strain of Kanzawaspider mite which was obtained by a long artificial selection procedureagainst chlorfenapyr in a laboratory on a colony of Kanzawa spider mitewhich had been collected in the field, has developed about a 300-foldresistance to chlorfenapyr.

In the case of benzoepin, cartap, thiocyclam and diafenthiuron, thisKanzawa spider mite is thought to originate from a colony which hadacquired resistance to these insecticidal agents prior to the time ofcollection in the field. These compounds all showed low effects.

TABLE II Evaluation Of The Effect Of Test Mixtures Against Female ImagoOf Kanzawa Spider Mite Which Have Acquired Resistance AgainstChlorfenapyr LC₅₀ TEST MIXTURE RATIO¹ ppm) T^(c) Chlorfenapyr +Benzoepin 1:12 230 270 Chlorfenapyr + cartap 1:10 230 950 Chlorfenapyr +Thiocyclam 1:10 230 110 Chlorfenapyr + Diafenthiuron 1:10 540 110¹Chlorfenapyr: Second active Ingredient T^(c) = Co-tonicity Coefficient

As can be seen from the data on Table II, the co-toxicity coefficient ofthe test mixtures is a value greater than 100, which is indicative ofstrong synergistic action.

What is claimed is:
 1. An insecticidal and miticidal composition whichcontains as active ingredients synergistically effective amounts ofchlorfenapyr in combination with one or more compounds selected from thegroup consisting of benzoepin, nereistoxin-type insecticidal agents anddiafenthiuron.
 2. The composition according to claim 1 wherein theactive ingredients comprise chlorfenapyr in combination with one or morenereistoxin-type insecticidal agents.
 3. The composition according toclaim 2 wherein the nereistoxin-type insecticidal agent is cartap orthiocyclam.
 4. The composition according to claim 1 wherein the activeingredients comprise chlorfenapyr in combination with benzoepin.
 5. Thecomposition according to claim 1 wherein the active ingredients comprisechlorfenapyr in combination with diafenthiuron.
 6. The compositionaccording to claim 1 wherein the chlorfenapyr is present in a ratio ofabout 1 weight part to about 0.01-100 total weight parts of one or morecompounds selected from the group consisting of benzoepin, cartap,thiocyclam and diafenthiuron.
 7. The composition according to claim 6wherein the ratio is about 1 weight part of chlorfenapyr to about 1-20weight parts of one or more compounds selected from the group consistingof benzoepin, cartap, thiocyclam and diafenthiuron.
 8. A process for thepreparation of a composition of claim 1 which comprises admixing theactive ingredients with an agrohorticulturally acceptable solid orliquid carrier.
 9. The process according to claim 8 wherein the activeingredients comprise chlorfenapyr in combination with one or morecompounds selected from the group consisting of benzoepin, cartap,thiocyclam and diafenthiuron.
 10. The process according to claim 9wherein the chlorfenapyr is present in a ratio of about 1 weight part toabout 1-20 weight parts of one or more compounds selected from the groupconsisting of benzoepin, cartap, thiocyclam and diafenthiuron.